1ded
From Proteopedia
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CRYSTAL STRUCTURE OF ALKALOPHILIC ASPARAGINE 233-REPLACED CYCLODEXTRIN GLUCANOTRANSFERASE COMPLEXED WITH AN INHIBITOR, ACARBOSE, AT 2.0 A RESOLUTION
Overview
The product specificity of cyclodextrin glucanotransferase (CGTase) from alkalophilic Bacillus sp. #1011 is improved to near-uniformity by mutation of histidine-233 to asparagine. Asparagine 233-replaced CGTase (H233N-CGTase) no longer produces alpha-cyclodextrin, while the wild-type CGTase from the same bacterium produces a mixture of predominantly alpha-, beta-, and gamma-cyclodextrins, catalyzing the conversion of starch into cyclic or linear alpha-1,4-linked glucopyranosyl chains. In order to better understand the protein engineering of H233N-CGTase, the crystal structure of the mutant enzyme complexed with a maltotetraose analog, acarbose, was determined at 2.0 A resolution with a final crystallographic R value of 0.163 for all data. Taking a close look at the active site cleft in which the acarbose molecule is bound, the most probable reason for the improved specificity of H233N-CGTase is the removal of interactions needed to form a compact ring like a-cyclodextrin.
About this Structure
1DED is a Single protein structure of sequence from Bacillus sp. with and as ligands. Active as Cyclomaltodextrin glucanotransferase, with EC number 2.4.1.19 Full crystallographic information is available from OCA.
Reference
Crystal structure of alkalophilic asparagine 233-replaced cyclodextrin glucanotransferase complexed with an inhibitor, acarbose, at 2.0 A resolution., Ishii N, Haga K, Yamane K, Harata K, J Biochem. 2000 Mar;127(3):383-91. PMID:10731709
Page seeded by OCA on Thu Feb 21 12:15:46 2008
